In-text Questions Set 1 Page Number 18 Acidic Solution And .
NCERT Solution for class 10 Science Chapter 2 Acids, Bases and SaltsIn-text questions set 1Page number – 181. You are given three test tubes. The three test tubes contain distilled water,acidic solution and the basic solution respectively. There is only red litmus paperavailable in order to identify what is there in each test tube. How will you find outwhat is in each of the test tubes?Solution: We can identify the content in each of the test tubes using red litmus paper. Thiscan be done by noticing the colour change of the red litmus paper. If the red litmus paper changes to blue colour the solution is a basic solution. If the red litmus paper experience no change in acidic solution. If the red litmus paper changes to purple colour the solution is distilled water.In-text questions set 2Page number – 221. Why should curd and sour substances not be kept in brass and copper vessels?Solution: Curd and sour food substances contain acids; these acidic substances combine withmetal. This reaction turns food to poison which damage people’s health.2. Which gas is usually liberated when an acid reacts with a metal? Illustrate withan example. How will you test for the presence of this gas?Solution: When an acid reacts with any metal, salt and hydrogen gas are formed.Metal Acid Salt Hydrogen gas3. Metal compound A reacts with dilute hydrochloric acid to produceeffervescence. The gas evolved extinguishes a burning candle. Write a balancedchemical equation for the reaction if one of the compounds formed is calciumchloride.Solution: As metal compound released is Calcium Chloride the gas evolved here is CO2.Hence metal A should be Calcium Carbonate. Hence the reaction between Calcium Carbonateand HCl isCaCO3 (s) 2HCl (Aq) CaCl2( Aq) CO2 (g) H2O (l)
NCERT Solution for class 10 Science Chapter 2 Acids, Bases and Saltsin text questions set 3Page number – 251. Why do HCl, HNO3, etc., show acidic characters in aqueous solutions whilesolutions of compounds like alcohol and glucose do not show acidic character?Solution: Release of H ion in water will make a compound acidic or non-acidic. Acids are thesubstance which upon dissociating with water results in production of Hydrogen ions. Somecompounds show acidic character as they dissociate in the aqueous solution which results inthe production of hydrogen ions (acids like HCl, HNO3).Compounds similar to glucose or alcohol do contain hydrogen element but they do not showsigns of acidic nature. The fact that the hydrogen in them will not separate as like the hydrogenin the acids. They will not separate to become hydrogen ions, on dissolving in the water.2. Why does an aqueous solution of an acid conduct electricity?Solution: Charged particles are responsible for the conductance of electricity in an acid. Thesecharged particles called as ions are the reason behind conductance of electricity in acid.3. Why does dry HCl gas not change the colour of the dry litmus paper?Solution: HCl does not give out Hydrogen ions, therefore HCl does not show any acidicbehaviour and colour of the litmus paper remain the same on reacting with HCl gas.4. While diluting an acid, why is it recommended that the acid should be added towater and not water to the acid?Solution: While diluting an acid, it is recommended that the acid should be added to waterand not water to the acid because if water is added to concentrated acid, it release huge amountof heat which may result in explosion and can cause acid burns on face, clothes and body parts.Hence it is safe to add acid to water but not water to acid.5. How is the concentration of hydronium ions (H3O ) affected when a solution ofan acid is diluted?
NCERT Solution for class 10 Science Chapter 2 Acids, Bases and SaltsSolution: When acid is added to water there will be a fixed amount of hydronium present inthe fixed volume of solution. If we dilute the solution hydronium ion per volume of solutiondecrease, this in-turn decreases Hydronium concentration in the solution.6. How is the concentration of hydroxide ions (OH–) affected when excess base isdissolved in a solution of sodium hydroxide?Solution: When base is dissolved in sodium hydroxide solution its hydroxide ions increasebut it will reach saturation at some point. After saturation point hydroxide ion concentration isnot affected even after adding base further.In-text questions set 4Page number – 331. You have two solutions, A and B. The pH of solution A is 6 and pH of solution Bis 8. Which solution has more hydrogen ion concentration? Which of this is acidicand which one is basic?Solution: In order to find the hydrogen ion concentration, we can use the rule that states,“The pH of any solution is inversely proportional to the hydrogen ion concentration”.Therefore, it means that the solution that has a lower pH number will have a higher hydrogenion concentration. Hence, solution A will have a higher hydrogen ion concentration. Inaddition, solution B will be basic and A will be acidic.2. What effect does the concentration of H (aq) ions have on the nature of thesolution?Solution: Hydrogen ion concentration decides the nature of the solution. If Hydrogen ionconcentration increase then solution turn acidic and similarly if Hydrogen ion concentrationdecreases then solution turn basic.3. Do basic solutions also have H (aq) ions? If yes, then why are these basic?Solution: Basic solutions has H ions, but hydroxide ions present in basic solution are morein basic solution. Hence Hydroxide ions turn solution to basic.4. Under what soil condition do you think a farmer would treat the soil of hisfields with quick lime (calcium oxide) or slaked lime (calcium hydroxide) or chalk(calcium carbonate)?
NCERT Solution for class 10 Science Chapter 2 Acids, Bases and SaltsSolution: If the soil is acidic in nature (PH below 7) then such field should be treated withquick lime (calcium oxide) or slaked lime (calcium hydroxide) or chalk (calcium carbonate).In text questions set 5Page number – 34-351. What is the common name of the compound CaOCl2?Solution: Common name of CaOCl2 is bleaching powder.2. Name the substance which on treatment with chlorine yields bleaching powderSolution: The substance which on treatment with chlorine yields bleaching powder is Calciumhydroxide.3. Name the sodium compound which is used for softening hard water.Solution: Sodium carbonate is the compound which is used for softening hard water.4. What will happen if a solution of sodium hydrocarbonate is heated? Give theequation of the reaction involved.Solution: Heating sodium hydrocarbonate yields sodium carbonate and carbon dioxide gas isliberated in the process.5. Write an equation to show the reaction between Plaster of Paris and water.Solution: The chemical equation for the reaction of Plaster of Paris and water isCaSO4.1/2H2O 3/2H2O CaSO4.2H2OExercise questionsPage number – 331. A solution turns red litmus blue, its pH is likely to be(a)1(b) 4(c) 5(d) 10Solution: Answer is 10 because litmus paper turns blue when reacts with basic solution (PHmore than 7). Hence 10 is the answer.2. A solution reacts with crushed egg-shells to give a gas that turns lime-watermilky. The solution contains
NCERT Solution for class 10 Science Chapter 2 Acids, Bases and Salts(a)NaCl(b) HCl(c) LiCl(d) KClSolution: Answer is HCl.Egg shells contains calcium carbonate, which on reaction with HCl liberates CO2 gas whichturn lime water to milky.CaCO3 2HCl CaCl2 H2O CO23. 10 mL of a solution of NaOH is found to be completely neutralised by 8 mL of agiven solution of HCl. If we take 20 mL of the same solution of NaOH, the amountHCl solution (the same solution as before) required to neutralise it will be(a) 4 mL(b) 8 mL(c) 12 mL(d) 16 mLSolution: Since 10 ml of NaOH requires 8 mL of HCL, 20 ml of NaOH require 8 x 2 16mL ofHCl Hence the answer id option d 16mL.4. Which one of the following types of medicines is used for treating indigestion?(a) Antibiotic(b) Analgesic(c) Antacid(d) AntisepticSolution: Indigestion is due to excess production of acid in the stomach. Medicines used totreat indigestion is called as Antacid.5. Write word equations and then balanced equations for the reaction takingplace when(a) Dilute sulphuric acid reacts with zinc granules.(b) Dilute hydrochloric acid reacts with magnesium ribbon.(c) Dilute sulphuric acid reacts with aluminium powder.(d) Dilute hydrochloric acid reacts with iron filings.Solution:(a) dilute sulphuric acid reacts with zinc granules: dilute sulphuric acid zinc Zinc Sulphate Hydrogen Gas H2SO4(aq) Zn ZnSO4(aq) H2(g)(b) dilute hydrochloric acid reacts with magnesium ribbon. dilute Hydrochloric Magnesium Magnesium Chloride Hydrogen Gas 2HCl(aq) Mg MgCl2(aq) H2(g)(c) dilute sulphuric acid reacts with aluminium powder. dilute Sulphuric Acid Aluminium Aluminium Sulphate Hydrogen Gas
NCERT Solution for class 10 Science Chapter 2 Acids, Bases and Salts 3H2SO4(aq) 2Al(s) Al2(SO4)3(aq) 3H2(g)(d) dilute hydrochloric acid reacts with iron filings. dilute Hydrochloric Acid Iron Ferrous Chloride Hydrogen Gas 6HCl(aq) 3Fe(s) 3FeCl2(aq) 3H2(g)6. Compounds such as alcohols and glucose also contain hydrogen but are notcategorised as acids. Describe an Activity to prove itSolution: Insert two nails on the wooden or rubber cork and place them on a beaker as shownin figure. Connect iron nail to a bulb, 6 volt battery and a wire connected to switch. Pour somealcohol or glucose so as to dip the nails in glucose or alcohol. Turn the switch on and you thesee the bulb not glowing despite of connection to switch. Now empty the beaker and add HCLsolution. This time bulb glows. This proves acid can conduct electricity but alcohol and glucosedoes not conduct electricity.7. Why does distilled water not conduct electricity, whereas rain water does?Solution: Distilled water does not contain any ionic compounds in it. Whereas rainwater has a lot, more compounds. Rainwater has dissolved acidic gas such as carbon dioxide from the air and that formscarbonic acid. This means that it has hydrogen ions and carbonate ions. Therefore, withthe presence of acids, rainwater can conduct electricity.8. Why do acids not show acidic behaviour in the absence of water?Solution: The acidic behaviour from acids is because of the presence of hydrogen ions.
NCERT Solution for class 10 Science Chapter 2 Acids, Bases and SaltsHydrogen ions can only be produced in the presence of water and therefore water is definitelyneeded if acids are to show their acidic behaviour.9. Five solutions A, B, C, D and E when tested with universal indicator showed pHas 4, 1, 11, 7 and 9, respectively. Which solution is(a) neutral?(b) Strongly alkaline?(c) Strongly acidic?(d) Weakly acidic?(e) Weakly alkaline?Solution: In increasing order of hydrogen ion concentration:pH 11(B) - pH 9(E) - pH 7(A) - pH 4(D) - pH 1 (B)PH11 - Strongly alkalinepH9 - weakly alkalinePH7 - NeutralpH4 - Weakly acidicpH1 - Strongly acidic10. Equal lengths of magnesium ribbons are taken in test tubes A and B.Hydrochloric acid (HCl) is added to test tube A, while acetic acid (CH3COOH) isadded to test tube B. Amount and concentration taken for both the acids aresame. In which test tube will the fizzing occur more vigorously and why?Solution: HCl is a strong acid whereas acetic is a weaker acid. Fizzing occurs because of theproduction of the hydrogen gas obtained due to reaction of the acid on the magnesium ribbon.Since HCl is a very strong acid there is a lot of liberation of hydrogen gas from test tube A.therefore, more fizzing take place in test tube A.11. Fresh milk has a pH of 6. How do you think the pH will change as it turns intocurd? Explain your answer.Solution: Fresh milk is turned to curd due to production of lactic acid. Lactic acid reduces thepH of the milk.12. A milkman adds a very small amount of baking soda to fresh milk.
NCERT Solution for class 10 Science Chapter 2 Acids, Bases and Salts(a) Why does he shift the pH of the fresh milk from 6 to slightly alkaline?(b) Why does this milk take a long time to set as curd?Solution: (a) He shifted the pH of the fresh milk from 6 to slightly alkaline to prevent milkfrom getting sour due to production of lactic acid.(b) This milk takes long time to set into curd because the lactic acid produced here firstneutralises the pH then the pH is reduced to turn milk to curd.13. Plaster of Paris should be stored in a moisture-proof container. Explain why?Solution: Plaster of Paris should be stored in moisture-proof container because moisture canaffect plaster of Paris by slowing down the setting of the plaster because of hydration. This willturn plaster useless.14. What is a neutralisation reaction? Give two examples.Solution: The reaction of the acid base gives a product of salt water, which is consideredas neutralization reaction.Examples:NaOH HCl NaCl H2OMg(OH)2 H2CO3 MgCO3 2H2O15. Give two important uses of washing soda and baking soda.Solution:Washing sodaBaking soda1.1.It can be used to test the garden soil foracidity. If bubbles are developed then the soilIs too acidicIt is used as an electrolyte2.It can be used domestically as watersoftener for laundry.2.If used on washing car then it willremove dead bug bodies without damagingthe colour or the paint on the car.
Solution: When acid is added to water there will be a fixed amount of hydronium present in the fixed volume of solution. If we dilute the solution hydronium ion per volume of solution decrease, this in-turn decreases Hydronium concentration in the solution. 6. How is the concentration of hydroxide
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Window Text Wrap Place text box with text be-tween 2 columns Open the text wrap window and select Wrap Around Object Shape. The body text should move away from your other text box. (never put a text box in the middle of a column) To fine tune the text box so text does not touch the edge of the
Making Connections Text-to-Text, Text-to-Self, Text-to-World Rationale Reading comes alive when we recognize how the ideas in the text connect to our experiences and beliefs, events happening in the larger world, our understanding of history, and our knowledge of other texts. "Text-to-Text, Text-to-Self, Text-to-World" is a strategy that helps
101 27 35 11 28 # TEAM TOTAL SET #1 SET #2 SET #3 SET #4 SET #5 SET #6 SET #7 SET #8 1 Fashingbauer 149 13 11 3 36 16 24 21 25 2 Thapa 394 53 82 55 49 63 33 49 10 # TEAM IMPs Total SET #1 SET #2 SET #3 SET #4 . He is a member of ACBL Unit 134, and he is currently an NABC Master. Reese is also the captain of his high school golf team.
Text Dependent Questions Use Text Based Evidence Running Records (conferencing) Exit Slips Text Dependent Questions RI4.1 - Refer to details and examples in a text when explaining what the text says explicitly and when drawing inferences from the text FOUNDATIONAL SKILLS (RF): Short Vowel Review Vowel Diagraph Review Closed Syllable Patterns Spelling Words (conferencing) Weekly Spelling Test .
text dependent questions, which is also appropriate at the primary level. As with the upper grades, the purpose of text dependent questions during reading is to tap into multiple aspects of a text. But for younger students lots of the questions during a first read will focus on text basics: finding evidence, identifying story parts if the text is literary, paraphrasing key passages to clarify .
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Quote accurately from a text when explaining what the text says explicitly and when drawing inferences from the text. Quote accurately from the text (explicitly and making inferences). 1 SR. Reading Informational Text 2: Determine two or more main ideas of a text and explain how they are supported by key details; summarize the text.
